Method and Apparatus for Testing Tubular Objects

Abstract

A method for testing tubular objects, in particular paper sleeves in a cylindrical pressure chamber, comprises the following steps: receiving the tubular object to be tested in a pressure chamber, which is comprised of a hollow cylinder with a pressure shell, wherein the pressure shell is supported at the hollow cylinder and wherein an expansion of the pressure shell in radial outward direction and in axial direction is limited; loading the pressure shell with a pressure means, so that the inner surface of the pressure shell is evenly applied to the surface of the object; and providing a pressure increase until the terminal pressure to be tested is reached, or a damage of the tubular object occurs. The invention also relates to an apparatus for testing tubular objects, configured to use the method.

1 . A method for testing tubular objects, characterized by the following steps:
 (a) receiving the tubular object to be tested in a pressure chamber, which is comprised of a hollow cylinder with a pressure shell supported at the hollow cylinder, wherein an expansion of the pressure shell in radial outward direction and in axial direction is limited;   (b) loading the pressure shell with a pressure, so that an inner surface of the pressure shell is evenly applied to a surface of the object; and   (c) providing a pressure increase until a terminal pressure to be tested is reached, or a damage of the tubular object occurs.   
   
   
       2 . A method according to  claim 1 , wherein an even pressure is applied to a cambered surface of the tubular object by the pressure shell. 
   
   
       3 . A method according to  claim 1 , wherein a liquid, a gel or a mix thereof is used as a hydraulic pressure. 
   
   
       4 . A method according to  claim 1 , wherein the expansion of the pressure shell is limited by the hollow cylinder and by flange disks at its ends, so that an expansion in a direction towards the tubular object is achieved. 
   
   
       5 . A method according to  claim 1 , wherein the pressure within the pressure shell is monitored by a manometer. 
   
   
       6 . A method according to  claim 1 , wherein detection of a sudden pressure drop indicates damage of the tubular object. 
   
   
       7 . A method according to  claim 1 , wherein an inner diameter is monitored by additional sensors. 
   
   
       8 . A method according to  claim 1 , wherein a change in length of the tubular object is monitored by sensors. 
   
   
       9 . A method according to  claim 1 , wherein a surface test of the tubular object and a test of geometric distortion is performed by a test apparatus. 
   
   
       10 . An apparatus for testing tubular objects, comprising a cylindrical pressure chamber for receiving the tubular object, a control unit and an additional pressure generating device, wherein the pressure chamber is defined by a hollow cylinder, which is made of metal, and in which a pressure shell is supported, which can be loaded by a pressure, wherein an inner surface of the pressure shell is applied to the tubular object when pressure is applied, while an outer surface is supported at the hollow cylinder, wherein an expansion of the pressure shell in radial outward direction, as well as an axial expansion of the pressure shell are limited. 
   
   
       11 . An apparatus for testing tubular objects according to  claim 10 , wherein the pressure shell is comprised of a flexible cuff. 
   
   
       12 . An apparatus for testing tubular objects according to  claim 10 , wherein the pressure shell can be loaded by a pressure, which can be inducted from an outside by a pressure connector. 
   
   
       13 . An apparatus for testing tubular objects according to  claim 10 , wherein the pressure connector is run through the hollow cylinder in outward radial direction. 
   
   
       14 . An apparatus for testing tubular objects according to  claim 10 , wherein the hollow cylinder is secured to flange disks at its face, which comprise an opening, which is adapted to an outer diameter of the tubular objects. 
   
   
       15 . An apparatus for testing tubular objects according to  claim 10 , wherein an pressure increase can be controlled by a manometer. 
   
   
       16 . An apparatus for testing tubular objects according to  claim 10 , wherein a pressure drop can be detected by a sensor in order to determine thermal damage to the tubular object. 
   
   
       17 . An apparatus for testing tubular objects according to  claim 10 , wherein an inner diameter of the tubular object and/or a change in length can be detected by sensors. 
   
   
       18 . An apparatus for testing tubular objects according to  claim 17 , wherein the sensors are monitored, and measurement values are stored, and pressure loading is controlled, wherein the stored information is relayed when required. 
   
   
       19 . An apparatus for testing tubular objects according to  claim 10 , wherein in case of a pressure drop, at least one of an optical signal generator and acoustic signal generator can be activated. 
   
   
       20 . An apparatus for testing tubular objects according to  claim 10 , wherein the pressure is generated by a generating device comprising at least one pressure container, a pump, and a feed line towards the pressure shell. 
   
   
       21 . (canceled) 
   
   
       22 . (canceled)